Strand coating apparatus



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G. H. FRANK STRAND COATING APPARATUS @W wpmm Filed Jan. 9, 1943 g a M Wm wm mw mw 1 bu NHQQ 2 3 h|l|lm h M mm 9% mm \m um Q July 31, 1945.

w Q Q Patented July 31, 1945 aaaoazz i s'raANn COATING APPARATUS GeorgeH. Frank, Oak Park, Ill., assignor to Western Electric Company,Incorporated, New York, N. Y., a corporation of New York ApplicationJanuary 9, 1943. Serial No. 471,893

6 Claims.

' vention, a plurality of baking ovens are provided in horizontalalignment, each oven having a separate-coating bath associated with itwhereby dili'erent compositions may be applied, to the wires travellingin a straight line and not bent from the time they enter the firstcoating bath until they are completely coated and each oven having aseparate baking tube for each strand to which heated air is fed underpressure, the tubes being bai'iled whereby the heated air may bemaintained under pressure therein. In the preferred form of theinvention, the wires are electrolytically cleaned and then highly heatedin an atmosphere to fuse down slivers just prior to their passage to thefirst coating bath.

A better understanding of the invention may be had by reference to thefollowing detailed description when considered in conjunction with theaccompanying drawing, wherein Fig. 1 is a schematic plan view ofapparatus embodying the invention;

Fig. 2 is a longitudinal sectional view taken substantially along theline 2--2 of Fig. 1 in the direction of the arrows:

Fig. 3 is an enlarged iragmentary sectional view also takensubstantially along the line 2-2 of Fig. 1 in the direction of thearrows and showing structural features of one of the coating baths andtheforward end of one of the ovens:

Fig. 4 is a fragmentary transverse vertical sectional view takensubstantially along the line 4-4 of Fig. 3 in the direction of thearrows; and

Fig. 5 is a fragmentary sectional view taken on the line 8-! of Fig. 3in the direction of the arrows showing the means for feeding the wirewithout bending it.

Referring to the drawing. wherein likereierence 1 characters designatethe same parts throughout the several views, it will be seen thatstrands of wire it to be coated are withdrawn from'supp'ly spools Iisuitably positioned adjacent th'e entrance .end oi the apparatus and,after being coated, are taken up on takeup spools i2 at the exit end ofthe apparatus- The strands i0 withdrawn from the spools 'II are passedover suitable guide sheaves it and then into engagementwith a contactroller it. The contact roller ll is'electrically connected to a suitablepower source, represented by the battery II, the other side of which isconnected to a tank it in which there may be placed a suitableelectrolyte il. Within the tank ll, there are provided four sets ofrollers i8. ll, 20 and II, the rollers II and 2t being so positionedthat their lower edges are beneath the electrolyte I! in the tank It andthe rollers i8 and 2| being positioned to direct the strands Hi to andfrom the rollers i9 and 20. The rollers i8, i9, 20 and 2i are insulatedfrom the tank i 6 in any suitable manner and thus the electrolyte I! inthe tank It will serve to remove all impurities from the surfaces of thestrands of wire III as the strands pass through the tank it.

Immediately after the strands of wire are guided over the rollers 2|,they pass into a highly heated chamber 21 provided with inlet and outletports 28 and 29, through which any suitable atmosphere, heated to a hightemperature, may be passed. The atmosphere used will depend upon thekind of wire being processed and the temperature of the gas in thechamber 21 should be maintained at such a point that slivers on the wirewill be fused down without, however. damaging the main body of the wire.Either hydrogen gas or nitrogen gas may be used in this chamber and'thetype of gas will depend. as pointed out hereinbefore, on the type ofwire which is being processed.

The strands of wire ill will be fed through the chamber 21 in a straightline, being drawn therethrough by a capstan 30. It should be noted atthis time that after the strands ofwire III are directed around thearrangement of guide rollers is to 2 I. through chamber 21 and aroundcapstan iii, the wire is not again bent until after it has beencompletely processed and reaches a capstan 22 at the exit end of theapparatus. As the strands of wire Iii leave the capstan 30, they will bedirected to a notch 3i (Fig. 5) formed in a feed sheave 32, of whichthere is provided one for each strand of wire. The feed sheaves 32 havethe notches 3i cut into them to form a narrow V in which the strands l0may rest and by which the strands will be driven without the necessityof wrapping the strands around the sheave. In this manner, the wire willnot be bent until the coating thereon is completed but will pass throughall of the ovens in succession in a straightline. The sheaves 32 aremounted within a casing 32 and may be driven by any suitable power means(not shown) for directing the strands of wire III to roller typeapplicators 24, having their lower halves extending into a bath 35 ofenamel in a tank 36. The applicators 34 may be driven to carry enamel 35up onto the wire or may be freely rotatable in the bath, being driven bythe strands of wire. The wires may enter the tank 28 through suitablenotches 31 cut inthe left-hand wall (Fig. 3) of the tank 88 and may passout of the tank 38 through notches 28 strands lo and to aid indistributing the enamel on the strands.

"Each of the strands of wire l0, after having enamel applied to it, willbe fed into a baking oven, designated generally by the numeral 4i whichincludes a large chamber 42 having an inlet port 43 through which ametered quantity of air may be fed from a suitable source of air underpressure (not shown). Within the chamber 42, there is positioned aheating element 44, over which a circulating fan 45 blows the airadmitted through the inlet port to maintain the air in the chamberconstantly circulating so that the temperature of the air throughout thechamber will be uniform. The air admitted through the inlet port 43,after being heated, will be fed into a series of baking tubes 41, ofwhich there is provided one for each strand fed into the ovens. Theinterior of the tubes 41 is in communication with the chamber 42,suitable apertures 46 being provided at approximately the middle of theupper surface of each tube to permit the heated air from the chamber toenter the tubes. The baking tubes 41 are provided with baffles 48extending downwardly and baflles 48 extending upwardly, these bamesbeing provided only at the entrance and exit ends of the tubes. In orderto facilitate the threading of the wires in the ovens, the end portions85 and 5B of the baking tubes 41 may be made in upper and lower halves50 and SI (Fig. 3) with the baffles 48 fixed in the upper half 50 andthe baiiles 49 fixed in the lower half ll. Each of the halves areslotted. as shown at 52, to form aligned passages through which thestrands l0 may pass through the ovens. In a suitable form of bakingtube, the lower half 5| may be fixed to end walls of the chamber 42 andthe upper half 50 of the end portions 55 and 54 of the tubes 41 may beremovable. The baiiles 48 and 49 will, in this construction, serve toproperly position the halves of the end portions of the tubes withrespect one to another. The end portions 55 and 58 of the baking tubesare positioned outside the baking oven 4|, as shown in Fig. 3.

The baking oven 4! and its associated parts maybe duplicated as manytimes as it is desired and two of them haye been shown in the drawing.In this manner, the strands of wire may be coated with enamel and theenamel baked on them without bending the wire until the baking of theenamel on the wire is completed and, accordingly, inner layers ofrelatively soft enamel may be covered by outer layers of relatively hardenamel or vice versa. Since the wire, in its passage through all of theovens, is not bent. but follows a straight line path, diflerent types ofcoating may be applied to the wire. For example. a hard coating whichwould crack and break of! the wire if wrapped around a guide roller maybe covered by a softer tough coating which will hold the hard coating inplace, although the hard coating cracks.

In the operation of the apparatus. the wire, after being threadedthrough the electrolytic cleaning bath l1 and silver removing chamber21. may be threaded through the ovens 4|, and. since each wire isenclosed in a separate tube, any breakage of a strand of wire III willnot damage other wires being processed. After the strands of wire Illhave been threaded through the ovens, the fans 45 may be started andheated air for drying the enamel on the strands II will be forcedthrough the apertures 44 and into the ass'olsaa tubes 41. In thismanner, a small pressure may be built up in the baking tubes and thefeeding of a small quantity of air through the chamber 42 and tubes 41will prevent cold air from entering the open ends of the tube, therebyto facilitate the baking of the enamel on the wire and to. accordingly,provide a more uniform coating. The provision of the feed sheaves 32with the notches 3| will feed the wires effectively without thenecessity of bending them.

What is claimed is:

1. In a wire enamelling apparatus. a plurality of baking ovens, acoating bath adjacent each oven, means for transferring coating materialfrom the baths to a wire. a blower in each oven, and a tube havingbaiiies therein positioned to surround the wire. said tube being incommunication with the blower and serving to maintain air delivered toit from the blower under pressure around the coated wire.

2. In a wire enamelling apparatus, a cleaning bath. a sliver removingchamber, a capstan for drawing wire from a supply through the cleaningbath and silver removing chamber, a takeup capstan for advancing coatedwire, a plurality of baking ovens intermediate said capstans arranged ina straight line, a baking tube individual to each oven, means forsupplying heated air under pressure to said baking tubes, a coating bathindividual to each of said ovens. and means adjacent to each coatingbath for advancing and supporting the wire between the baking ovens tocarry the wire in a straight line during the coating and baking thereof.

3. In a wire. enamelling apparatus, a plurality of coating bathsarranged in horizontal alignment, a plurality of ovens in horizontalalignment with said coating baths, applicators at each coating bath fortransferring coating material from the bath to the wire. and advancingand supporting means at each bath comprising sheaves having annularV-notches for gripping and advancing the strand tangentially of saidsheaves.

4. In a wire enamelling apparatus, a plurality of coating baths arrangedin horizontal alignment. a plurality of ovens in horizontal alignmentwith said coating baths, applicators at each coating bath fortransferring coating material from the bath to the wire, and sheavesadJacent the baths provided with cooperating surfaces to grip the wireand advance it by the engagement of said surfaces with the wire onlythrough a small arc whereby the strand travels in a sub- 5. In a wireenamelling apparatus, a plurality of ovens arranged in tandem. a coatingbath adjacent one end of each of said ovens, a takeup capstan fordrawing wire from the last oven in the tandem arrangement. groovedsheaves having surfaces for gripping and advancing the wire adjacenteach oven, means for electrolytically cleaning a wire before it entersthe first oven, and a sliver removing means intermediate the cleaningbath and the first oven.

6. In a wire enamelling apparatus. the combination with a plurality ofcoating baths and a plurality of baking ovens. of a sliver removingmeans comprising a chamber through which a wire to be coated is drawn.and means for supplying a highly heated inert gas to said chamber tofuse the slivers.

GEORGE H. FRANK.

